Regardless of which controls etc it'd be nice to change to make them more intuitive, you'll have to make sure that you're not going to run foul of the following:
FAR 25.777
FAR Part 25 Sec. 25.777 effective as of 12/01/1978
FAR 25.779
FAR Part 25 Sec. 25.779 effective as of 08/20/1990
FAR 25.781
FAR Part 25 Sec. 25.781 effective as of 08/20/1990